Internal combustion engine



0a. 1s, 193s. K, H. SCHLAE'FKE 2,133,418

INTERNAL GOMBUSTION ENGINE Filed oct. 21. 1956 2 sheets-Sheet 1 v @f1 llf/ Fly/5'A W 6 j; 4, ne

mez. H/i/ys MAE/wf Patented Oct. 18, 1938 PATENT OFFICE INTERNAL COMBUSTION ENGINE rml um schlanke, mnkfort-on-'the-Mnn,

Germany, assignor to' Adlerwe'rkc vorm. Heinrich Kleyer Aktiengesellschaft, Frankfortonthe-Main, Germany Application October 21, 1936, Serial No. 106,727 In Germany October 31, 1935 s claim. (ci. 12s-s3) o The invention relates to an internal combus- `tion engine in which the `fuel is injected into a combustion chamber which has a constricted communication with the working space of the cylinder and is of a size only slightly smaller than that of the entire compression space of the cylinder.

In all injected fuel internal combustion engines l one of the main problems is to reduce the delay l0 in ignition as far as possible, as the smooth running of the machine is largely dependent thereon.

Apart from the air density, the composition of the mixture (amount 'of excess air) and the degree of atomization (injection pressure), the degree of turbulence is one of the external factors which considerably affects the commencement of the self-ignition and thus the magnitude of the delay in ignition.

Consequently, many and diverse measures have l0 already been proposed in order to improve lthe turbulence of the air in the combustion chamber both in respect of its nature and its extent. It

is important that the whirl of the air should as far as possible occur in a well dened direction so as to prevent with certainty the conveyance of exhaust gas instead of fresh air to the fuel particles by the whirl. The object of the invention is to ensure by simple means that whirling should be produced to an adequate extent in an Si) invariable defined direction in the combustion chamber.

This object is attained in that the combustionv chamber communicates with the working chamber by way of two conduits or sets of conduits of 55 which one is so constructed that the resistance to y flow therethrough is greater for a ow towards the combustion chamber than in the opposite dio rection, and the othe'l'icgc that the resistai'ce to flow therethrough 4is greater for aow/to'wards tu the working space 'of the cylinder-than in the opposite direction. In this way an.` invariably constant direction of flow is produced both by the y I .U the other conduit or setof conduits, in which the` relative resistance to ilow is greater for a flow towards the combustion chamber, is materially smaller. Consequently, there results in the coml bustion chamber a relative iiow of air which is 55 directed from the end of the conduit or group of conduits, which has a smaller resistance to ilow `for a ow towards the combustion chamber, to

the end of the conduit (group of conduits) which has a greater resistance to ow for a ow towards the combustion chamber. l 5

On the return stroke vof the working piston, this direction of flow persists irrespective of whether the combustion creates an excess pressure. in the combustion chamber or whether the working. piston draws in fresh air. During these l0 working operations the gas in the combustion chamber will be forced or drawn at relatively high speed through the conduit in which the relative resistance to flow is smaller for a -ilow towards the working space of the cylinder, where- 1i as the speed of the gas which emerges from the conduit in which the relative resistance to ilow is greater for a flow towards the working space of the cylinder, remains small. Thus in this case also, the ilow in the combustion chamber is di- 20 rected from the end of the conduit which hasw. smaller resistance to flow for a flow towards the combustion chamber, to the end of the conduit which has a greater resistance to ilow for a iiow towards the combustion chamber. 25 'I'he eiect of the inventive feature is that superimposed on the alternating flow ,which is pro duced by the working piston or by the excess pressure created in the combustion chamber by the combustion, is a flow which is constantly directed from the end of one conduit (group of conduits) to the end of the other conduit (group of conduits).

Preferably the effect of the different resistances to flow for flows inthe two directions in the cona5 duits, is increased by making two conduits or groups of conduits of diierent cross sections. In

general, it will be advisable for the cross section of the conduit (group of conduits) which has a .smaller resistance to lflow for a ow towards the 40 working space of the cylinder, to be somewhat greater than the cross-section of the other conduit (group of conduits). In this way a particularly easy transfer of the gas from the combustion-chamber to thrfworking space of the cylinder is obtained during the combustion without excessively high pressures occurring in the combustion chamber.

'I'he most diverse methods are possible formaking the resistances to ow in the conduits different in the two directions. For example, the. conduits may for this purpose be provided with hooks pointing in the direction offlow` or otherwise formed to. make the conduits more or less eilective as non-return valves which interrupt or retard the flow therethrough in one direction. In the present arrangement, the diiliculties generally arising on providing moving parts within the combustion space are reduced as these non-return valve-like: conduits do not need to close tightly in the closed position. A particularly simple and appropriate construction resides in forming the connecting conduits after the manner of nozzles in such a way that the transition-to the smallest cross section occurs gradually on one side and abruptly on the other side.

A particularly suitable utilization of the flow within the combustion chamber is obtained if the conduit in which the relative resistance to iiow is smaller for a flow towards the combustion chamber, disclnrges into the combustion chamber tangentially. In this way a whirling ilow of air which ensures a particularly long path of the air and the direction of ow of which is satis- 80 factorily determined, is obtained withinthe combustion chamber. It is advisable for the other conduit or group of conduits also to enter the combustion chamber tangentially in such manner that the whirling flow is assisted.

z5 'I'he arrangement of the conduits or groups of conduits is preferably such that where the ends of the connecting conduits are substantially tangential to the combustion chamber, the

' section of the latter is disposed approximately l0 at right angles to the direction of the jet of fuel. In this way a progressive whirling of the air is obtained along the jet of fuel. To assist this longitudinal flow it is advisable that the conduit which has a relatively smaller resistance to flow for a ow towards the combustion chamber be inclined somewhat with respect to the cross section of the combustion chamber which is at right angles to the jet of fuel, the inclination being towards the conduit which has a relatively greater resistance to flow for a flow towards the combustion chamber. A-In a corresponding way `the last mentioned conduit may be arranged so as to be inclined in the opposite direction.

In general, the conduit or groups of conduits exhibiting a smaller resistance to flow for a. flow towards the combustion chamber is preferably arranged in such manner that it terminates in the chamber approximately at the point at which the jet of fuel enters the chamber, whereas the other resistance to flow for a flow towards the working space of the cylinder terminates approximately at that side of the combustion chamber which is remote from the point of entry of the jet of fuel.

diverse forms of combustion chambers. Preferably the combustion chamber is pear shaped in such a manner that the jet of fuel enters the chamber approximately at the smallest cross section.

A particularly convenient embodiment of the inventive idea resides in that the conduit or group of conduits in which the relative resistance to flow is smaller for a flow towards the combustion chamber than for a flow inthe opposite direction, embraces the combustion chamber wholly or in part. In this embodiment th'e combustion chamber is suitably in the form of a constructional element which is inserted separately. In this way the chamber is adequately cooled and nevertheless is maintained at a denite temperature which remains constant to a vcertain extent even with variations in the quantity of air supplied. This is particularly valuable in view of the fact that in some circumstances it The invention can be utilized with. th'el most` Fig'. 3 is a section along the line III-III of Fig. 1.

Figs. 4 and 5 show another embodiment of the invention, Fig. 4 being a section through the cylinder head and the upper part of the cylinder -along theline IV-IV of Fig. 5 and Fig. 5 a. section along the line V-V of Fig. 4.

Figs. 4a and 4b are enlarged fragmentary sectional views taken on the lines IVaf-Iva and IVb-IVb respectively, of Fig. 4.

Fig. 6 is a section through the cylinder head and the upper part of the cylinder of a further embodiment of the invention, and

Fig. 7 is a fragmentaryfsection along the line VII- VII of Fig. 6 on a larger scale.

Fig. 3 is an enlarged fragmentary view'similar to Fig. 1 and illustrating a modified form of c'onstruction.

Fig. 9 is an enlarged fragmentary sectional view taken axially through a modiiied form of construction.

' In Figs. 1 and 2, the fuel nomle is inserted into the combustion chamber I at the point 2. vApproximately at the point where the jet of fuel enters the combustion chamber I, a conduit 3 communicates with. the combustion chamber. The resistance to iiow in this conduit for a flow towards the combustion chamber is smaller than for a flow in the opposite direction. As shown in Fig. 3 this conduit 3 enters the chamber ap' The two conduits 3 and l connect the combustion chamber I with the working space 5 of the cylinder. The size of the combustion chamber is only slightly smaller than the total compresversely the point of entry'of the conduit 4 into the combustion chamber is well rounded off and the termination at the working space of the cylinder is sharp edged so that for both conduits a different resistance to *flow for flows of opposite directions is obtained due to the effect of this nozzle-like construction. Ofthe openings indicated at-S in the plan view, one is intended for theiinlet valve and the other for the outlet valve.

'I'he relative cross sectional areas of the con- -ofi' edge of the conduit 3 leading `to the work ing space, and the sharp ,edge leading to the combustion' chamber, the conduit .3 voders a greater resistance to flow from the combustion chamber to the working space than it ,does from the working space to the combustion chamber. As the point of entry of the :conduit 4 into'the combustion chamber is rounded on and the point of entry into the working space has'a sharp edge, Jthe conduit 4 offerslessresistanceto flow from the combustion' chamber tothe working space than it does from the 'working space to-the combustion chamber.. For repeatedkcycles there will therefore be a general flow of gas within the combustion chamber I from the conduit 3 ltoward the conduit 4." This will be evident when it is considered that for a pressure above the conduits 3 'and- 4, a particle of gas will flow toward the conduit-4 with less"res'istance andl will flow toward or through the conduit Iwith greater resistance than is the case when a pressure is applied to the working chamber. When a pressure is applied to the working chamber thesesame'particles will be moved back toward their original positions, in which event the particle or stream which moves toward or through conduit 4 will be moved back a less distance than it was moved forward for the pressure within chamber I. The particle within chamber 3will be moved back toward vits original position a greater distance for the pressure in the working position than it was moved toward the conduit 3 for the pressure in the 'combustion chamber.

In eect, differences in resistance will cause this latter named particle to have moved past its original positiontoward conduit 4. The result isv that for cycles of operation, the resultant movement of the particles is toward the conduit `4. Thisis true regardless of the relative areas of the conduitsr3 .and 4 and is caused by the conduits having differences in resistance to flow in opposite directions.

The same effect of obtaining a relatively greater flow of air from the combustion chamber I toward the working space in the engine cylinder than in the opposite direction as is obtained by flaring the upper end ofthe' conduit g 4 in Fig. 1 may be obtained in the manner illustrated in Fig. 8. This latter figure illustrates the hooked construction previously referred to in that the conduit or passage 29, corresponding with the passage 4 previously described, has sharp edges where it enters the working space in the cylinder. Its opposite end by means of which it communicates with the combustion chamber I is reversely curved as at 32 and is partially baiiied from the chamber I by the baille/ 3| which is more or less hooked toward the corresponding end of the conduit 29. As rwill be understood the provision of the hook or baille 3| will assist and increase the retarding eiect of the sharp lower edges of the conduit 29 in resisting flow through the conduit 29 toward the chamber I. l

the direction of the stroke of the piston.

9 and I0 which have `a smaller resistance to flow for a flow towardsthe combustion chamber than for a.'l Vflow in the opposite direction enter the chamber approximately at the point where the fuel jet enters the chamber. In this embodiment also the combustionl is somewhat pear-shaped.

Three conduits I I, I2, I3 which have a greaterl resistance to flow for a flow towards the combustion chamber than for a flow in the opposite direction enter the combustion chamber'at its lower end, i. e. at the point where it is of approximately maximum cross section. The conduits 9 and I9 and the conduits II, I2, I3

may enter the combustion chamber substantially outwardly as indicated at 21 in Fig. 4 so that the I 'rne fue1 nome is introduced into thecombustion chamber at the point I.' The two conduits resistance to flow therethrough from the work-y ing space in the engine cylinder toward the combustion chamber] is less than Vfor-a flow in the opposite direction. The end of the conduit.

I I at the point where it enters the working space of the engine cylinder is provided with sharp ledges while the opposite end where it enters the combustion chamber 'I is-fiared as indicated at 23 in Fig. 4b, the result being that'the ristance to flow through the conduit II is greater in the direction from the working space in the engine. l

-working space I4. One of the two openings I5 serves to receive the-inlet valve and the lother vto receive the exhaust valve.

The construction and arrangement of the combustion chamber can be modified to a far-reachi ing extent. For example, the combustion chamber may be arranged. relatively to lthe longitudinal axis of the cylinder `at any angle departing from 90.

In Fig. 6 the combustion chamber I3 is somewhat pear-shaped as in the preceding embodiments and is constituted by a separate insertion I9 which is mountedin a neck-shaped portion 20.

of the cylinder head. -The fuel nozzle is introwhich forms a connection between the combustion chamber I8 and the working space 23. The conduit 22 is constructed in the form of a nozzle in such manner that its resistance toflow for a flow towards the combustion chamber is greater than for a flow in the opposite direction. l

The neck-shaped part 20 vof the cylinder head embraces the insertion I9 constituting the combustion chamber I3 in such manner than an annular conduit is formed about the combustion chamber and the longitudinal sections 25, 23 of ,the annular conduit are nozzle-shaped. This annular conduit terminates approximately at the point of entry of 'the jet of fuel into the cdm-` bustion chamber I8 at openings 24 which are approximately tangential to the cross sectionwhich is disposed at right angles to the direction of the j'et of fuel. The nozzle-like form of the individual longitudinal sections 25, 23 is such that their resistance to flow for a flow towards the combustion chamber is smaller than for a flow in the opposite direction.

In this embodiment there is therefore a ilow of uniformly constant direction along the annular conduit through the openings 24 and along the combustion chamber I8 back to the working space.

In Fig. 9 is4 illustrated another form of hooked conduit construction that may be' Aemployed for the conduits connecting the combustion chamber with the working space in the engine cylinder in order to obtain a greater resistance to flow therethrough in one direction than in the opposite direction. The construction shown in Fig. 9 has the e'ect of providing multiple hooks. The conduit is shown as being interiorly provided with a plurality of axially spaced radially inwardly projecting annular hook-sectioned ribs or bailles 33. The maximum diameter of the conduit is illustrated at d and as occurring axially between the baffles 33. The minimum diameter is illustrated at c and as occurring at the points of the hooks. 'Ihe lower face of each baille 33 as Viewed in Fig. 9 is disposed radially of the conduit and terminates at its radially inner edge in a sharp edge. The upper face of each baiiie 33 as viewed in Fig. 9 is gradually curved from its outer diameter d to its inner diameter c in a manner such as to promote ease of fluid flow thereover. in such direction. The result of this construction is that air or other fluid attempting to ow through the conduit in the direction of the arrow `a meets and is retarded by contact with the successive radially extending shoulders of the baiiies 33 which also exercise a wire drawing eiect in the flow of the fluid over their sharp radially inner edges, while fluid owing through the conduit in the opposite direction indicated by the arrow b, flows over the smoothly curved upper surfaces of the bailies 33 which accordingly offer very little resistance and substantially no wire drawing effect to such flow. Thus the resistance to ow through the conduit in the direction of the arrow a is materially more than in the direction of the arrow b. In employing this form of conduit in any of the. previously described constructions the conduits will, of

course, -be arranged with the radially disposed faces of the bailles 33,'facing the direction in which less resistance to flow through the conduit is desired.

Formal changes may be-made in the specic embodiments of the invention described without departing from the`spirit or substance of the broad invention, the scopeiof which is commensurate with the appended claims.

I claimt- 1,)An`internal ,combustion engine of the kind set forth, including a combustion chamber, conduits extending between saidlcombustiom-chamber and the working space nf the cylindr. ami providing independent paths of flow between them, at least one of said conduits offering a greaterresistance to a ow towards the com.- bustion chamber than to a now in the opposite direction, whereas the remainder of. said conduits 'oier a greater resistance to a flow towards the working space than to a flow in the opposite direction, and means for injecting fuel into said combustiontufchamber in a direction generally I from said re'nainder of said conduits toward said one of said conduits.

2. An internal combustion engine according tp claim 1, inwhicheach conduit is constructed with an outwardly flared wall at one end and a relatively sharp edge at the other end.

3. An internal combustion engine according to claim 1, in which each conduit having a greater resistance to a flow towards the working space than for a now in the opposite direction is Y formed substantially tangential to the walls of s. An internal combustion engine of the kind`V set forth including a combustion chamber and means for injecting fuel thereinto, conduits openinginto the working space of the cylinder independently of one another extending between the workingl space of the cylinder and the combustion chamber remote from the point of entry of the fuel, at least one conduit offering a greater resistance to ow for a flow towards the combustion chamber than for a flow in the opposite direction, and extending between the working space of the cylinder and the combustion chamber adjacent the point of entry of the fuel, at least one further conduit offeringv a smaller resistance to now for a ilow towards the combustion chamber than for a flow in the opposite direction.

7. An internal combustion engine oi' the kind set forth including a combustion chamber, conduits extending between said combustion chamber and the working space of the cylinder having openings entering said combustion chamber independently of each other t'o provide independent communications between the engine cylinder and the combustion chamber, at least one of said conduits offering a greater resistance to a ilow towards the combustion chamber than to a now in the opposite direction, whereas the remainder set forth including a.combustion chamber and 1 means for injecting fuel thereinto, a conduit ex` tending between the working space of the cylinder and the combustion chamber remote from the point of entry of the fuel, said conduit offerl ing a greater resistance to flow for a flow towards the combustion chamber than for a now in the opposite. direction, and at least one other conduit extending between the working space of the cylinder and the combustion chamber adjacent the point of entry of the fuel, the last mentioned conduit oifering a` smaller resistance to ow for' into said combustion chamber to provideindependent communication between the engine cylinder and the combustion chamber.

KARLHANSSCHLAEFKE.V 

